Part of the investigation into Thursday's crash that killed one person and injured more than 110 others will focus on a safety system that prevents trains from colliding, derailing or speeding, according to Bella Dinh-Zarr, vice chairman of the National Transportation Safety Board.
"That is absolutely one area that we always look into for every rail accident," Dinh-Zarr said of the technology, which is called positive train control.
New Jersey Transit trains don't have it -- they operate on a safety system that has been in place for nearly 40 years.
Congress originally required the newer technology to be operational by the end of 2015. However, it extended the deadline to the end of 2018 to avoid a possible shutdown of the nation's railroads.
"Every PTC-preventable accident, death and injury on tracks and trains affected by the law will be a direct result of the missed 2015 deadline and the delayed implementation of this life-saving technology," NTSB Chairman Christopher Hart said earlier this year.
The cause of Thursday's crash is unclear as of now. However, Dinh-Zarr said investigators will be looking at a 2011 crash in Hoboken that injured 33 people.
That crash was caused by "the failure of the engineer to control the speed of the train entering the station," according to the NTSB.
The lack of a positive train control system also contributed. The agency said it "would have intervened to stop the train and prevent the collision."
New York Gov. Andrew Cuomo said it's too early to know whether PTC could have made a difference in Thursday's crash. What we do know is that the train was going very fast when it entered the station, where the speed limit is just 10 mph.
Bhagyesh Shah, who was riding in the back of the front car, said the train didn't appear to slow as it entered the station.
"The next thing I know, I'm on the floor," he said. "We are plowing through something ... and when the train came to a stop. I could see the parts of the roof on the first car and some of the debris next to me."
An event recorder recovered from the locomotive will reveal the train's speed and other information, Dinh-Zarr said.
What the NJ Transit trains DO have
Dinh-Zarr didn't know whether the train was equipped with an "alerter" system, which requires engineers to respond to alerts, sound an alarm if they are unresponsive and eventually brake the train in an emergency.
The New Jersey Transit uses a less comprehensive system known as Automatic Train Control (ATC) to slow speeding trains, said Steve Ditmeyer, a former Federal Railroad Administration official and professor at the University of Delaware.
ATC has been in place throughout the Northeast corridor -- the most heavily traveled rail network in the country -- for nearly 40 years. The system notifies an engineer if a train is speeding and applies the brakes automatically if the engineer does not respond.
The engineer working that day is critical to this investigation. He was critically injured in the crash.
Newer safety system is costly
Many publicly financed railroads, including the New Jersey Transit, have been slow to switch to the newer technology because of the cost, Ditmeyer said.
"There (has) just been a continuous series of accidents that could have been prevented with PTC," he said.
"I'm not sure if this (accident) is going to make (PTC implementation) go any faster, but we again see how important this system is."
The railroad industry has opposed PTC
because of the high cost and technological issues.
Many freight railroads already use it -- but it came with a hefty price tag. Freight rail companies spent nearly $6.5 billion to develop PTC, and they have retained more than 2,400 signal system personnel to implement it, according to the Association of American Railroads
Some experts have floated other ideas to increase safety.
David Rangel, president of the Modoc Railroad Academy, said putting another person in the engineer's cab -- a practice common in airplane cockpits and many freight lines -- could help prevent accidents if the engineer becomes incapacitated.
65 deaths. 1,100 injuries. Millions in damages.
The NTSB has said positive train control could have prevented numerous railroad accidents involving human error.
Since 2004, the agency has investigated at least 25 train accidents that have killed 65 people, injured more than 1,100 and caused millions in damages -- all of which could have been prevented or mitigated by positive train control.
The NTSB often cites a handful of deadly crashes to drive home the need for PTC:
- December 2013: A Metro-North train derailed in the Bronx, killing four and injuring dozens. The engineer fell asleep and didn't slow the train from more than 82 mph to the maximum authorized speed of 30 mph as it entered a curve.
- May 2015: An Amtrak train derailed in Philadelphia, killing eight and injuring more than 200. The train's engineer was distracted after his attention was diverted to an emergency involving another train.
"Unless positive train control is implemented soon, I'm very concerned that we're going to be back in this room again, hearing investigators detail how technology that we have recommended for more than 45 years could have prevented yet another fatal rail accident," Hart said when findings on the Philadelphia crash were released.